1. Field of the Invention
The present invention relates to a table type display device capable of achieving high resolution display at the time of displaying the large screen, by projecting luminous flux for the image formation from a plurality of projectors on the screen of the horizontal location type.
2. Related Art Station
As a conventional table type display device to project the luminous flux to form the image on the screen of the horizontal location type, for example, there are the device of the type displaying images on the LCD panel, and device of type shown in FIG. 18, by burying one LCD panel of the order of 10–14 inches in a horizontal plane of a table-like casing. The conventional table type display device shown in FIG. 18 corresponds to the device described in FIG. 3 of Japanese Patent Laid-open No. 305,079/2000, and comprises one projector 51 for projecting luminous flux to form an image, two reflection mirrors 52 and 53 for bending an optical path of luminous flux projected from the projector 51 twice, and a transparent screen 54 of the horizontal location type, from which luminous flux bent two times, is projected to an optical path by these reflection mirrors 52 and 53, which are built in a same casing 55, the casing 55 is constituted in the shape of the desk, and a transparent screen 54 constitutes the desk plane (table plane).
The conventional table type display device show in FIG. 18 adopts a construction in which the luminous flux projected from one protector 51 is projected through two reflection mirrors 52 and 53 on a transparent screen 54, so that resolution of the projector and displaying resolution on the screen are the same. Therefore, for example, even in case of utilizing a projector with the resolution of XGA (1024×798 pixels), the resolution on the screen becomes only XGA, and when the screen is made a large screen, the displayed image rather becomes unclear and becomes hard to see. Therefore, in the above conventional display device, it is difficult to achieve the high resolution display at the time of displaying the large screen.
In the display device, as a method of achieving high resolution display at the time of displaying large screen, for example, as described in Japanese Patent Application Opened No. 326981/1997, which has been filed previously by the present applicant, there is a method of displaying one image on the entire screen, by projecting the luminous fluxes to form the images from a plurality of projectors to a predetermined region of the screen constituted to the large screen respectively.
When the screen constituted to the large screen, is horizontally located to constitute the table type display device, the screen is bent by the self-weight of the screen, and is bent by loading a part or all of the weight of the viewer on the screen. In that case, the display image is distorted and blurred, and thus the display quality is deteriorated, so that the flexure of the screen must be reduced.
Moreover, in case of projecting the luminous flux to form the image from a plurality of projectors to a predetermined region of the screen constituted to the large screen, respectively, the incident angle of luminous fluxes in the periphery of respective regions becomes large compared with the incident angle of luminous flux in a central portion thereof, so that the boundary of the adjoining area looks dark, and the connection stands out, and thus the visual performance of the display image is different according to the standing position of the viewer.